got a problem. ive been doing setups for years. and ive been told im better than sam ash and guitar center and all that (im a perfectionist to say the least).

my question/problem is. the g-string doesnt buzz, but it kinda warbles in and out when played (around the 12th fret mostly). i have only had this problem with a couple guitars.

any tips for getting rid of this problem? it ruins the sustain and just flat out doesnt sound good
Are you using the right thickness of strings according to length, wood-type of your neck??

It seems a tension problem to me, but I might be wrong. Would like to hear what other people have to say
i think the string gauge has a lot to do with it, but i also think that there is no set string gauge to a certain kind of guitar.

i experimented with all of that for about 3 years. spent maybe 200 dollars on string experiments. turns out you can "SRV" it with just about any guitar.

unless i missed your point?
I think that may just be a fret issue. Maybe it's popped up from the fretboard itself? Easiest way to test is to dip a toothpick in water and place a drop at the base of the fret. If it sinks underneath, your fret is letting go underneath.
R.I.P. Les Paul, 1915-2009

A man chooses, a slave obeys.
i agree with the fret theory except for the fact that it only happens on one string. thats why im confused. the irony is the g-string is set the highest at this point
The fret may just be letting go in that spot, or maybe the nut/saddle has a barb or something in it that's screwing stuff up.
R.I.P. Les Paul, 1915-2009

A man chooses, a slave obeys.
good call, i dont know if that was it or not, i just adjusted the truss rod and everything too. intonation is in well. i dunno, its happened on a couple guitars over the years, i guess thats why i think its a common problem.
I had an old knockoff Strat that did that. Wish I would have kept it,. that thing would have been a great practice guitar.
R.I.P. Les Paul, 1915-2009

A man chooses, a slave obeys.
Are these guitars mostly gibson style with angled headstocks and 3 tuners per side?

I'm thinking that your stringing style doesn't end low enough at the tuning machine, so that the break angle over the nut is too shallow. Another possibility is that the tailpiece isn't at the right height and you're getting sympathetic vibration in the string between the bridge and tailpiece.
theyre all strat style guitars. and im not sure. that might be it too, the string too high or low at the nut thing i mean.
They may be non-staggered tuners with only one string tree. Some tuner sets aren't as big of a problem with it, but some do need the second tree.
R.I.P. Les Paul, 1915-2009

A man chooses, a slave obeys.
ahh, thats probably it!!! my tele plays fine and so does my squier strat, but they both have two trees. my new fender mexican strat has only one small tree on it